For 65 years, Carl Lytle has made his rounds. When he started there were no beepers; no penicillin. He entered medical school before vitamin C was discovered. He brought the first electrocardiograph machine to Marion County in 1939 and built its first nursing home in 1965.

So this gantlet was easy. He took questions, checked charts and headed toward the elevator.

At 90, he's one of the oldest active doctors in the nation and perhaps the oldest still making house calls. Through study, he keeps current. Through choice, he keeps dispensing an old-fashioned brand of comfort learned in the early 1900s from a doctor in Pennsylvania. His childhood hero: Uncle Ralph.

''There's Dr. Lytle,'' a woman said to her mother sitting in a wheelchair. ''This is who I wanted you to see.'' The doctor in his white coat glanced at the 88-year-old stroke victim.

''Can you see my mother?'' Diane Faulkingham asked.

Well, after 62 years of seeing the sick of Central Florida, he wasn't about to start dodging patients now. He led them to a side room in the Marion House Health Care Center, one of three nursing homes where he is medical director. Then he leaned over.

''How are you doing today?''

Helen Wray couldn't answer because of the stroke. So Dr. Lytle laid his hand on hers. She lifted her other hand, and it wavered a few inches above the doctor's.

Faulkingham was worried about her mother's foot. Dr. Lytle bent down, took hold of the heel and gently spread the toes apart. ''See, there. It's purple,'' the daughter said, pointing out a small splotch. ''Is it OK?''

Dr. Lytle stood up. ''Just about like mine,'' he said. Then he lifted his leg and shook his foot.

''Yes,'' she said, smiling. Yes, she nodded. If Doc Lytle said it was OK, it was.

Most of Ocala's streets were dirt roads when Dr. Lytle returned from Jefferson Medical College in Philadelphia in 1935.

He bumped along in a Model-A Ford, delivering babies at scattered farmhouses with his inflatable mattress and its attached stirrups for women in labor.

Penicillin was many years away. At times, all he could offer was mustard plasters and peace of mind. It was the Great Depression. House calls were $3. Sometimes all his patients could give were hens and hogs.

Today, he drives a Buick Regal Gran Sport and listens to medical tapes as he glides along on highways he knew as grass trails. The trails have become streets. The streets crowded with houses.

The houses full of friends, the friends, many of them, now dead.

''Lost him a year ago,'' he said, pointing to a home he drove by. ''Took care of his brothers,'' he said, passing another. ''Lost him a couple years ago,'' he said of a lawyer. ''Active doctor lives there. Retired doctor lives there.''

Dr. Lytle almost retired once. A heart attack slowed him when he was in his early 60s. He took time off, vacationed with his wife, eventually grew restless. A memory kept coming back.

It was 1914. He was 8. His family lived in the small town of McKeesport near Pittsburgh. The local hardware store was run by Alexander Stewart, whose son, Jimmy, grew up to be an actor. It was a pleasant time to be a kid. Then the pneumonia hit. Lytle got very sick: shallow breaths, high fever, delirious.

His parents sent for Uncle Ralph Lytle, a doctor in the nearby town. Young Carl had drifted in and out of nightmares, but when he opened his eyes, he saw his uncle by his bed. He was a tall man with a commanding presence and comforting way.

Like all doctors back then, he had little of medicinal value. But his confidence made the child feel better. The fever soon broke. And in its place a dream burned.

The boy remembered it when his father moved the family to Florida for a healthier clime. The young man followed his dream as he worked his way through the University of Florida. And the student lived it as he learned medicine at his uncle's alma mater, with a loan from Uncle Ralph.

Eighty-two years later, the doctor still keeps his dream alive. And it keeps him going.

Carolyn, his wife of 58 years, died in 1995. His daughter and granddaughter work in his office. But many friends are dead.

His practice consists mostly of the elderly now. He takes calls from nursing homes at night and drives to houses of longtime patients who can't come to him.

It's caretaking, not miracle working. He realizes other doctors don't find it exciting. He didn't either when he was young.

''It's really a devotion,'' said Peg Masino, a registered nurse who worked with Dr. Lytle and wrote a book about him. ''He's got something to give. He wants to keep giving it.''

C. Brooks Henderson, a semi-retired psychiatrist who has known Dr. Lytle for 33 years, said his colleague stays sharp. Indeed, his son-in-law's mother goes to him.